freebsd-dev/usr.bin/cmp/cmp.c

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/*
* Copyright (c) 1987, 1990, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char copyright[] =
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"@(#) Copyright (c) 1987, 1990, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static const char sccsid[] = "@(#)cmp.c 8.3 (Berkeley) 4/2/94";
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#endif /* not lint */
#include <sys/types.h>
#include <sys/stat.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "extern.h"
int lflag, sflag;
static void usage __P((void));
int
main(argc, argv)
int argc;
char *argv[];
{
struct stat sb1, sb2;
off_t skip1, skip2;
int ch, fd1, fd2, special;
char *file1, *file2;
while ((ch = getopt(argc, argv, "-ls")) != -1)
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switch (ch) {
case 'l': /* print all differences */
lflag = 1;
break;
case 's': /* silent run */
sflag = 1;
break;
case '-': /* stdin (must be after options) */
--optind;
goto endargs;
case '?':
default:
usage();
}
endargs:
argv += optind;
argc -= optind;
if (lflag && sflag)
errx(ERR_EXIT, "only one of -l and -s may be specified");
if (argc < 2 || argc > 4)
usage();
/* Backward compatibility -- handle "-" meaning stdin. */
special = 0;
if (strcmp(file1 = argv[0], "-") == 0) {
special = 1;
fd1 = 0;
file1 = "stdin";
}
else if ((fd1 = open(file1, O_RDONLY, 0)) < 0) {
if (!sflag)
err(ERR_EXIT, "%s", file1);
else
exit(1);
}
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if (strcmp(file2 = argv[1], "-") == 0) {
if (special)
errx(ERR_EXIT,
"standard input may only be specified once");
special = 1;
fd2 = 0;
file2 = "stdin";
}
else if ((fd2 = open(file2, O_RDONLY, 0)) < 0) {
if (!sflag)
err(ERR_EXIT, "%s", file2);
else
exit(1);
}
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skip1 = argc > 2 ? strtol(argv[2], NULL, 0) : 0;
skip2 = argc == 4 ? strtol(argv[3], NULL, 0) : 0;
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if (!special) {
if (fstat(fd1, &sb1)) {
if (!sflag)
err(ERR_EXIT, "%s", file1);
else
exit(1);
}
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if (!S_ISREG(sb1.st_mode))
special = 1;
else {
if (fstat(fd2, &sb2)) {
if (!sflag)
err(ERR_EXIT, "%s", file2);
else
exit(1);
}
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if (!S_ISREG(sb2.st_mode))
special = 1;
}
}
if (special)
c_special(fd1, file1, skip1, fd2, file2, skip2);
else
c_regular(fd1, file1, skip1, sb1.st_size,
fd2, file2, skip2, sb2.st_size);
exit(0);
}
static void
usage()
{
(void)fprintf(stderr,
"usage: cmp [-l | -s] file1 file2 [skip1 [skip2]]\n");
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exit(ERR_EXIT);
}